The Experts below are selected from a list of 306 Experts worldwide ranked by ideXlab platform
Christophe Caloz - One of the best experts on this subject based on the ideXlab platform.
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Uniform Ferrite-Loaded Open Waveguide Structure With CRLH Response and Its Application to a Novel Backfire-to-Endfire Leaky-Wave Antenna
IEEE Transactions on Microwave Theory and Techniques, 2009Co-Authors: Toshiro Kodera, Christophe CalozAbstract:A Uniform ferrite-loaded open waveguide Structure with composite right/left-handed (CRLH) response and its application to a novel backfire-to-endfire leaky-wave antenna are presented. The Structure consists of a ferrite-filled rectangular waveguide open to free space at one of its small sides and biased perpendicularly to its large sides. Based on the fact that the leakage from the open side represents only a small perturbation in terms of guidance, an analytical dispersion relation for the approximately equivalent perfect magnetic conductor closed waveguide Structure is derived. The unique dispersive properties of this Structure, including its inherent CRLH balanced response (gapless nonzero group velocity transition between the left- and right-handed bands) and low-loss characteristics due to off-resonance operation, are extensively described, parametrically studied, and concretized by design guidelines. This theory is validated by both finite-element method and finite integration technique full-wave results and demonstrated experimentally. The leakage of the Structure is exploited to build a full-space backfire-to-endfire scanning leaky-wave antenna, which is capable of both fixed-bias frequency scanning and fixed-frequency bias scanning, while being a perfectly Uniform Structure not requiring any chip tuning components. This feature, and its subsequent design simplicity, represents a fundamental advantage over previous CRLH metmaterial implementations. To the best of our knowledge, the proposed ferrite waveguide is the first and unique Uniform Structure exhibiting a CRLH response.
J.i. Sewell - One of the best experts on this subject based on the ideXlab platform.
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Mixed switched and digital network simulation
1997 IEEE International Symposium on Circuits and Systems (ISCAS), 1997Co-Authors: Z.q. Shang, J.i. SewellAbstract:In the development of the latest suite of SCNAP software for switched network analysis, much effort has been directed towards producing highly efficient algorithms, very versatile packages and a Uniform Structure with a simple user interface. These principles have been utilised further in the design of SCNAP5, which interfaces with the commercial logic simulator Verilog to produce a most effective mixed-mode simulator, capable of delivering very detailed analysis of mixed-mode SC and SI circuits. A number of examples are given to illustrate the application of the software.
Mohammad Mehdi Zahedi - One of the best experts on this subject based on the ideXlab platform.
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Uniform AND SEMI-Uniform TOPOLOGY ON GENERAL
2020Co-Authors: M. Horry, Mohammad Mehdi ZahediAbstract:In this paper, we define the concepts of compatibility between two fuzzy subsets on Q, the set of states of a max- min general fuzzy automaton and transitivity in a max-min general fuzzy automaton. We then construct a Uniform Structure on Q, and define a topology on it. We also define the concept of semi-Uniform Structures on a nonempty set X and construct a semi-Uniform Structure on the set of states of a general fuzzy automaton. We then construct a semi-Uniform Structure on , the set of all finite words on , the set of input symbols of a general fuzzy automaton and, finally, using these semi- Uniform Structures, we construct two topologies on Q and and discuss their properties.
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Uniform AND SEMI-Uniform TOPOLOGY ON GENERAL FUZZY AUTOMATA
Iranian Journal of Fuzzy Systems, 2009Co-Authors: M. Horry, Mohammad Mehdi ZahediAbstract:In this paper, we define the concepts of compatibility between two fuzzy subsets on Q, the set of states of a maxmin general fuzzy automaton and transitivity in a max-min general fuzzy automaton. We then construct a Uniform Structure on Q, and define a topology on it. We also define the concept of semi-Uniform Structures on a nonempty set X and construct a semi-Uniform Structure on the set of states of a general fuzzy automaton. We then construct a semi-Uniform Structure on Σ∗, the set of all finite words on Σ, the set of input symbols of a general fuzzy automaton and, finally, using these semiUniform Structures, we construct two topologies on Q and Σ∗ and discuss their properties.
Hiroshi Fudouzi - One of the best experts on this subject based on the ideXlab platform.
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fabricating high quality opal films with Uniform Structure over a large area
Journal of Colloid and Interface Science, 2004Co-Authors: Hiroshi FudouziAbstract:Abstract Films of opal, a colloidal crystalline lattice with closely packed Structure, are anticipated to become a fundamental material in photonic crystal engineering. One of the technological issues is forming the opal film with a flat and Uniform surface over a large area. This article describes a new and simple method for forming an opal film without special equipment. The opal film is formed by drying a colloidal suspension covered on a hydrophilic solid substrate. In the conventional method, a ring-shaped opal usually forms at the edge (contact line) of the suspension on the substrate. The new method improved the process of drying the colloidal suspension free from the ring formation. The driving force of this ring formation is based on capillary flow in the suspension from inside to outside because of the high evaporation rate at the contact line. To prevent capillary flow, the contact line of the suspension was covered with hydrophobic silicone liquid. As a result, ring formation was depressed and flat opal films with Uniform Structure were formed. The Structure comprised cubic closely packed (111) planes, and the opal films were grown to grain sizes larger than 200 μm. In addition, the coating area of the opal film was greater than 75 cm2 using a 4-in. silicone wafer. This new method should be useful for coating high-quality opal film over large areas on solid substrates.
Toshiro Kodera - One of the best experts on this subject based on the ideXlab platform.
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Uniform Ferrite-Loaded Open Waveguide Structure With CRLH Response and Its Application to a Novel Backfire-to-Endfire Leaky-Wave Antenna
IEEE Transactions on Microwave Theory and Techniques, 2009Co-Authors: Toshiro Kodera, Christophe CalozAbstract:A Uniform ferrite-loaded open waveguide Structure with composite right/left-handed (CRLH) response and its application to a novel backfire-to-endfire leaky-wave antenna are presented. The Structure consists of a ferrite-filled rectangular waveguide open to free space at one of its small sides and biased perpendicularly to its large sides. Based on the fact that the leakage from the open side represents only a small perturbation in terms of guidance, an analytical dispersion relation for the approximately equivalent perfect magnetic conductor closed waveguide Structure is derived. The unique dispersive properties of this Structure, including its inherent CRLH balanced response (gapless nonzero group velocity transition between the left- and right-handed bands) and low-loss characteristics due to off-resonance operation, are extensively described, parametrically studied, and concretized by design guidelines. This theory is validated by both finite-element method and finite integration technique full-wave results and demonstrated experimentally. The leakage of the Structure is exploited to build a full-space backfire-to-endfire scanning leaky-wave antenna, which is capable of both fixed-bias frequency scanning and fixed-frequency bias scanning, while being a perfectly Uniform Structure not requiring any chip tuning components. This feature, and its subsequent design simplicity, represents a fundamental advantage over previous CRLH metmaterial implementations. To the best of our knowledge, the proposed ferrite waveguide is the first and unique Uniform Structure exhibiting a CRLH response.
